Plastic metal.



CHARLES LEEiALEXANDER, 0F CHARLOTTE, NORTH CAROLINA.

, PLASTIC METAL.

Specification of Letters Patent.

Patented Oct. 8, 1912.

No Drawing. Original application filed April 26, 1910, Serial No.557,749. Divided and this application filed Iuly'19, 1911. Serial No.639,461.

To all whom it may concern:

Be it known that 1, CHARLES L. ALEX- ANDER, a citizen of the UnitedStates, residing at Charlotte, in the county of Mecklenburg and State ofNorth Carolina, have invented certain new and useful .Improve- 'ments inPlastic Metal; and I do hereby dc clare the following to be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to which it a pertains to make and use thesame.

his invention relates to the 'production of plastic metal and theprocess of making the same and is a division of application SerialNumber 557.,74- 9, filed April 26th, 1910.

In the aforesaid pending application the description refers to thepreferred form as consisting of employing finely divided or powderedmetal, as gold which is bound together by a binder. Reference is alsomade to the use of sponge or moss gold and the present application isdirected to the latter specific form of the invention.

In carrying out the invention it is found more desirable, under someconditions, to employ what is known in the trade as sponge gold .or mossgold instead of finely divided or powdered gold. When such sponge ormoss gold is employed it is of course unnecessary to employ what wouldbe strictly a binder, as the metallic fibers are connected to form anintegral metallic mass, but one wherein the fibers are separated byinnumerable interstices. In addition to retaining the metallic particlesin union it is also necessaryto prevent adhesion. In the use of moss orsponge gold, or an equivalent, the substance which in co-pendingapplication 557,749 is termed a binder, is more especially a lubricantto prevent the adhesion of the particles and whileas ordinarily employedit serves also as a binder, it will be termed herein a lubricant, itbeing understood that the same function is performed by such lubricantas is performed by the binder in said co-pending application. Thelubricant may be any oleaginous or waxy material but preferably a wax isemployed which is soft when warm and which becomes harder when chilledand capable of complete dissipation by heat. As the use of oils would bealmost self evident in connection with the sponge or moss gold, the useof the waxy lubricant will be described in like, and dip detail. Thewaxy lubricant is applied to the sponge or moss gold in a number ofdiffer. out ways, one of which is dipping the spongy mass into the waxwhile warm and in a fluidcondition so that a thin coating adheres to thesurface. Another and perhaps preferable method is to dissolve the wax ina solvent such as benzin, amyl-acetate or the the gold into thissolution. Upon removing the gold from the solution, the solventevaporates and leaves the wax coating the gold' throughout its entireextent, within the interstices and without. The coating can be made ofany desired thickness by employing a solution more or lessnearly'saturated. This latter method is especially convenient inconnection with sponge gold on account of the fact that a very smallproportion of wax can be applied to the metal and it is not necessary toconipress it or heat it to remove the excess. It is desirable to secureas great a density of the metal as possible in the practical applicationof this product and therefore it is only advisable to use the smallestpossible amount of waxy lubricant as a coating.

Prepared as above described, the plastic metal is employed in a varietyof ways but preferably in dentistry, in which art it lends itselfadmirably to the making of cast inlays, crowns and the like. In themaking of inlays the cavity of the tooth having been properly cleanedout and made ready, the plastic metal is forced into place and thecavity filled with it exactly as if it were to be a permanent filling.The plastic metal is then employed in exactly the same manner that'thewax is employed in the ordinary casting of a dental inlay althoughinvesting, dissipating of the waxy binder and the introduction of moltenmetal is much less complicated than ordinarily practiced. Heat isapplied to dissipate the lubricant from the metallic mass leaving themold within the investment completely filled with the metallic mass, butsuch metallic mass filled with interstices. Solder is now melted in thecrucible and, by the capillary attraction of thcinterstices, themetallic mass is immediately drawn into the mold to comreo and of beingsolidified when cold.

of clearly indicating theexact nature of the metal. The presentinvention is, not limited to the use of sponge gold or moss gold or goldof any condition, but is applicable to -all metals in spongy fibrousmass which may ffl ."A"mass composed of metal in fibrous; fstatepresenting interstices filled with a waxy binder capable of plasticityat a tem-:

perature which will not cause discomfort "when applied to a part of thehuman anatp Q the fibers in a mass and permit the fibers to :omy, andofbeing soldified when cold.

2. A-mass composed of metal in the form; of fibersupres'entinginterlying interstices; -filledwith awaxy binder capable of beingfmanipulated to move the metal parts onef upon the other withoutseparation or adhe-; slon when warmed to a temperature which:

.Will not cause discomfort when applied to; "a part of the humananatomy, and of becom-j 5'55 ing less plastic as it is cooled.

3. A mass composed of metallic fibers} having the interstices filledwith a waxy.

binder capable of plasticity at a tempera-'; ture which will not causediscomfort when; applied to a part of thehuman anatomy,-

4. A mass composed ofmetal in the form of connected fibers having theinterstices I filled with a waxy binder capable of plasticity at atemperature which will not cause discomfort when applied to a part ofthe human anatomy and of being solidified when cold.

5. A mass composed of metal of spongy formation having the intersticesfilled with a waxy binder capable of .plasticit at a temperature whichwill not cause iscom-" fort when applied to a part of the human anatomy,and of being solidified when cold.

6. A mass composed of metallic connected fibers having the surfaces ofthe fibers coated with a lubricant adapted to retain be manipulated tomove one upon the other when the massdswarmed to. a temperature whichwill not cause discomfort when. ap I plied to a being solidified whencold and being completely dissipated by heat.

7. A mass composed of metal in 'spong-y art of the human anatomy, of"

condition having the surfaces of the component fibers covered with alubricant capable

